The relationship between angiography, intraerythrocytic pH and hemoglobin oxygen equilibrium

The acute effects of an injection of contrast material (Renovist) on intraerythrocytic and extracellular pH was studied at cardiac catheterization in 72 patients with congenital heart disease. A decrease in mean extracellular (plasma) pH (7.444 plus or minus .006 to 7.419 plus or minus 0.009) and an increase in mean intraerythrocytic pH (7.204 plus or minus .005 to 7.232 plus or minus .006) were observed within minutes after injection (p smaller than .01). In 17/72 patients, simultaneous measurements of oxygen affinity for hemoglobin as characterized by P50 (oxygen tension at 50% O-2 saturation) corrected to in vivo arterial pH decreased from a mean of 26.4 to 25.2 mm Hg (p smaller than .01). It is postulated that the acute increase in intraerythrocyte pH and increased affinity of hemoglobin for oxygen are due to a decrease in intracellular hydrogen ion concentration induced by the increase in plasma osmolality with subsequent shift of hemoglobin oxygen equilibrium via the Bohr effect.

Pulmonary artery sling

Pulmonary artery sling is an uncommon and potentially lethal vascular anomaly that can produce airway obstruction. Despite the availability of a corrective operation, the mortality rate remains very high (50 per cent of surgically treated children) due to the high incidence of associated obstructive anormaliies of the tracheobronchial tree. The survivors of corrective operation have done well symptomatically. However, when restudied, most have been found to have no pulmonary blood flow to the left lung. Successful treatment requires early recognition of the anomaly, adequate preoperative investigation for associated anormalies (especially those of the tracheobronchial tree), a technically perfect vascular reconstruction, and meticulous postoperative respiratory therapy.

Bacterial endocarditis in children under 2 years of age

The risk of bacterial endocarditis in infants with bacterial sepsis was assessed by review of clinical and autopsy records (1930 to 1972). There were 12 cases of bacterial endocarditis among 847 patients (1.4%) dying with bacterial sepis; a single survivor was noted during the entire period. Of the 12 autopsy patients, six had underlying congenital heart disease (CHD). Among 61 patients with bacterial sepsis associated with CHD, six acquired bacterial endocarditis (10%), whereas in 786 infants with sepsis but without underlying heart disease, only six developed bacterial endocarditis (0.8%) (P less than .01). There is a high mortality in infants with bacterial endocarditis, and an increased risk of it in infants with sepsis and CHD.

Photoamidation of unsaturated carbohydrates. Synthesis of 1-(3-C-carbamoyl-3-deoxy-beta-D-glucopyranosyl)-thymine and -cytosine

The acetone-initiated photochemical addition of formamide to 1,2,4,6-tetra-O-acetyl-3-deoxy-alpha-D-erythro-hex-2-enopyranose (1) afforded 1,2,4,6-tetra-O-acetyl-3-C-carbamoyl-3-deoxy-alpha-D-glucopyransoe (2), 1,2,4,6-tetra-O-acetyl-3-C-carbamoyl-3-deoxy-alpha-D-allopyranose (3), 1,2,4,6-tetra-O-acetyl-3-C-carbamoyl-3-deoxy-alpha-D-altropyranose (4), and 1,2,4,6-tetra-O-acetyl-3-deoxy-3-C-(1-hydroxy-1-methylethyl)-alpha-D-mannopyranose (5), in 46, 13, 1, and 7% yields, respectively. Condensation of 2,4,6-tri-O-acetyl-3-C-carbamoyl-3-deoxy-alpha-D-glucopyranosyl bromide (produced from 2 with hydrogen bromide) with 2,4-bis(trimethylsilyl)thymine afforded 1-(2,4,6-tri-O-acetyl-3-C-carbamoyl-3-deoxy-beta-D-glucopyranosyl)thymine (6) in 40% yield. Deacetylation of 6 with sodium methoxide in methanol yielded the pure unprotected nucleoside 7. Similar condensation of the bromide from 2 with 2,4-bis(trimethylsilyl)-N4-acetylcytosine afforded the protected cytosine nucleoside 8 in 55% yield, which was converted into 1-(3-C-carbamoyl-3-deoxy-beta-D-glucopyranosyl)cytosine (9).

Constrictive pericarditis in childhood due to mediastinal irradiation

Between 1955 and 1972, eight children receiving mediastinal irradiation for intrathoracic malignancy developed constrictive pericarditis. Six of these followed irradiation for Hodgkin's disease and represent 7% of 86 children receiving irradiation for that disease. In patients with Hodgkin's disease, the development of constrictive pericarditis was related to the dose of radiation and the use of orthovoltage technique. Constrictive pericarditis has not yet developed among the 44 children radiated by supravoltage technique. Symptoms of constrictive pericarditis occurred an average of 15 months (4/12 to 3 2/12 years) after irradiation and were preceded in five of the eight patients by acute pericarditis. Prominent clinical findings included dyspnea, Kussmaul sign, pulsus paradoxicus, hepatomegaly, cardiomegaly and electrocardiographic evidence of low QRS voltages with ST-T wave changes. Pericardiectomy was performed in six patients and resulted in immediate but only transient symptomatic relief. There was no operative mortality. Death occurred in six of the eight patients (1 5/12 to 6 6/12 years following irradiation) due to cardiac disease in three, progression of the malignancy in two and infection in one. In addition to constrictive pericarditis, extensive myocardial fibrosis and involvement of the antero-lateral papillary muscle and chordae tendineae of the mitral valve were demonstrated at postmortem examination. These factors may explain the progression of cardiac disease despite an initial symptomatic improvement following pericardiectomy.

The use of heparinization to prevent arterial thrombosis after percutaneous cardiac catheterization in children

Thrombosis at the site of arterial puncture is a common and serious complication of percutaneous cardiac catheterization in children. A double-blind study was therefore designed to test the efficacy of heparin administered during catheterization in reducing this complication. One hundred and sixty-one unselected children over one year of age were studied. Prior to catheterization, the pulse amplitudes were measured in both legs using a Pulse Volume Recorder (a standardized oscillometer). Immediately after arterial cannulation, heparin, 1 mg/kg, or a placebo was administered. On the morning following catheterization, the pulse amplitude in both legs was remeasured and a pulse volume index calculated using the uncatheterized leg as a control. Patients in whom the catheterized leg was cold, with poor capillary filling and absent arterial pulses four hours after the completion of catheterization, were started on intravenous infusion of heparin. If no improvement occurred within 48 hours, embolectomy was performed.

There was no evidence of arterial compromise to the catheterized extremity to any patient older than 10 years. Of 77 children ten years of age or younger, systemic heparinization postcatheterization was required for a pulseless extremity in 40% (15/37) of those in the placebo group and 8% (3/40) in the heparin group ( P = 0.003). Only 5% (2/40) of children in the heparinized group had a pulse volume index of less than 50%, compared to 27% (10/37) in the placebo group ( P = 0.003). Embolectomy was performed in seven of the 37 children in the placebo group and none of 40 in the heparin group ( P = 0.01). No complications related to the use of heparin were found. We conclude that heparin administered during percutaneous catheterization is effective in preventing arterial thrombosis in children ten years of age or younger and should be routinely administered unless a specific contraindication to its use exists.

Critical pulmonary stenosis with a diminutive right ventricle in neonates

Thirteen of 19 neonates seen in the first months of life with critical pulmonary stenosis (PS) and an intact ventricular septum had a diminutive right ventricle (RV) evidenced by electrocardiographic and angiocardiographic criteria. All were critically ill and at catheterization had hypoxemia secondary to right-to-left shunting at the atrial level, and RV hypertension. Right ventricular angiogram was useful to evaluate RV size and differentiate the children with PS from those with pulmonary atresia.

Pulmonary valvulotomy was the procedure of choice and in ten children the operation resulted in marked improvement with disappearance of cyanosis and cardiomegaly within one year. All are well six months to eight and one half years later. Two children had an additional unrecognized infundibular stenosis and required a shunt after valvulotomy because of persistant cyanosis. One child had a shunt without valvulotomy and died three years later in congestive failure.

The three children who have been recatheterized at two to three years postoperatively have RV pressures less than 60 mm Hg. In two the right ventricles more than doubled in size but remain small.

These children are critically ill and a good salvage rate depends on rapid evaluation and valvulotomy.

Development of subaortic stenosis after pulmonary artery banding

Palliation of children with large ventricular septal defects (VSD) by pulmonary artery banding (PAB) is associated with a variety of unfavorable sequelae. We document another possible complication of PAB, the development of subaortic stenosis, which occurred in 4 of 40 infants with large VSD and PAB. Prior to surgery all had congestive heart failure, cardiomegaly, pulmonary plethora, and biventricular or right ventricular hypertrophy on electrocardiogram. At cardiac catheterization all had large VSD with pulmonary artery hypertension. No gradient between left ventricle and systemic artery was demonstrated. PAB was followed by improvement in all four children. Repeat catheterization at 4 to 11 years of age revealed that they had developed a significant (30 to 100 mm Hg) gradient across the left ventricular outflow tract.

Although the etiology of the subaortic stenosis is not known, it is felt that the hypertrophied and possibly leftward deviated conal septum was impinging on the left ventricular outflow tract in three of the four.

Since the subaortic stenosis was not suspected prior to the second catheterization, we feel that preoperative evaluation of children with VSD and PAB should include evaluation of the left ventricular outflow tract to be certain that no obstruction is present.

Cardiac manifestations of Marfan syndrome in infancy and childhood

The clinical profile and course of 36 infants and children with Marfan syndrome is reviewed. Cardiac abnormalities were present in 61% of the patients and were the major cause of death. Mitral regurgitation, the most frequently encountered cardiac lesion (47%), occurred in both males and females, while aortic regurgitation was present only in males. Arrhythmias were observed in four patients, and congenital heart disease (atrial septal defect) was observed in one. A distinguishing auscultatory feature was an apical mid or late systolic murmur preceded by single or multiple clicks. A characteristic electrocardiographic pattern of S-T segment and T-wave changes in leads II, III, aV F , and left precordial leads was noted in 11 patients. The prognosis of children with Marfan syndrome and isolated mitral regurgitation was usually good, whereas patients with combined mitral and aortic regurgitation had a rapidly deteriorating clinical course. The overall mortality in the group was 14%.

Cardiomyopathy in Noonan's syndrome. Report of 3 cases

Images

Influence of acute variations in hematocrit on the QRS complex of the Frank electrocardiogram

The influence of acute variations in hematocrit on the QRS complex of the Frank scalar electrocardiogram was studied in 31 patients with severe polycythemia secondary to cyanotic congenital heart disease and in eight patients with anemia due to thalassemia. Moderate reduction of the hematocrit in the polycythemic group resulted in a significant increase in the magnitude and a delay in both left maximal spatial voltage (LMSV) and maximal anterior force. Raising the hematocrit in the anemic group decreased the magnitude of LMSV and maximal anterior force. A change in the orientation of the spatial vector frequently accompanied induced variations in the hematocrit. Experimental and theoretical studies suggest that alterations in the hematocrit and, hence, intracardiac electrical resistivity distort the magnitude and orientation of the surface-recorded QRS voltages. It is postulated that the effect of high intracavitary blood hematocrit in polycythemia in reducing early QRS voltages is due to its influence on radial myocardial excitation propagated from endocardium to epicardium. Anemia, on the other hand, enhances the voltages due to radial spread of impulses in the myocardium, resulting in an increased magnitude of the LMSV and usually also of the maximal anterior force.